Back-pressure joint



Patented Dec. 16, 1930 NITED STATES PATENT OFFICE JOHN D. LEMEX, OFTULSA, OKLAHOMA, ASSIGNOR, BY MES NE ASSIGNMENTS, TO OIL -WELL SUPPLYCOMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF NEW JERSEYBACK-PRESSURE JOINT Application filed June 5, 1928. Serial No. 283,011.

My invention relates to a tool joint and back pressure valve structure,and more particularly to a drill pipe float joint or coupling designedfor connecting adjacent sections of a drill pipe, and primarily employedin lowering or floating a drill pipe into a well in order to reduce theweight of the pipe being handled, for the purpose of reducing the strainand wear on the equipment em- 1 ployed for lowering the drill pipe intoposition in a well.

The prime object of the present invention is to provide a strong,durable and eflicient joint or coupling of the character specified andof such construction that, in case the valve mechanism is renderedinoperative, an uninterrupted passage of fluid through the coupling maybe effected.

Other objects of the present invention are, to provide a back-pressureor float valve coupling having an integral valve seat formed on areduced portion of the coupling, and having an adjustable valve guidemounted in an enlarged portion of the coupling below said valve, saidguide being of such character that the area of the opening or openingstherein. for the passage of fluids therethrough. is greater than thearea of the valve and a spring-controlled valve of improved constructionfor controlling the passage of fluids through the coupling.

In the accompanying drawings, which illustrate an application of myinvention:

Fig. 1 is a vertical sectional View of a joint or coupling member andback pressure valve embodying my invention; and

Fig. 2, a top plan view of the valve guide member.

Referring to the drawings, the joint or coupling comprises a hollow body5 constituting. as illustrated. a hollow pin member 6 and a box-member7. Box-member 7 at its upper end is formed with a tapered interiorlythreaded pin-receiving portion 8, into which a lower threaded taperedportion 9 of the pin member is entered. The opposite end of said membersare adapted to receive the adjacent ends of two drill pipe sections Aand B. and are each threaded, as shown at 10 and 11 respectively.

is preferably of the form shown, and in-.

cludes an elongated stem 16 formed integral with the valve roper. Thisstem is slightly reduced, as at 1%, and this reduced portion is adaptedto be projected through a stem-receiving portion 18 of the valve guidemeans or member 12. Valve has a conical contacting seating surface (1adapted to make a close fit with the inclined face of valve seat 1 19designates a coil spring having an end thereof seated upon portion 18 ofthe guide means and its other end disposed in an annular recess 20 ofthe valve. Spring 19 exerts suflicient pressure on the valve to maintainthe valve on its seat during the operation of lowering the drill pipeinto the well, and the valve will remain in its closed position untilthe circulating fluid is admitted to the drill pipe and the pressure ofsaid fluid overcomes the pressure of the spring and any other pressurebelow the valve.

The guide member 12 is designed to be adjustably supported within thelarge portion of the coupling, and for this purpose it has an annularthreaded portion 21 having its threads engaging the threaded portion 11of box member 7. The preferred form of member 12 is particularly shownby Fig. 2 of the drawings, and as there shown, it is formed withradially extending members 22 extending from the stem-receiving portion'18 to its annular portion 21, and with large openings 23 for thepassage of fluids through the guide member. The combined area of thesefluid passages 23 is greater than the area of the valve 15, thusensuring an uninterrupted passage of the circulating fluid through thecoupling at all times, even should the valve or its stem break and fallonto the gulde.

I claim:

1. A drill pipe float joint comprising a hollow body havin an interiorlyextending portion integral tfierewith formed with a reduced boreportion, said portion on one side being ad: ted for abutment by theadjacent element of the drill pipe line and on its other side providinga valve seat, a valve guide within and supported by the hollow bodybelow the seat, and a spring pressed valve interposed between the guideand the seat, said guide having a fluid passage area greater than thevalve area to permit of an uninterrupted flow of fluid through thejoint.

2. A drill pipe float joint comprising a hollow body having aninteriorly extending portion integral therewith formed with a reducedbore portion, said portion on one side being adapted for abutment by theadjacent element of the drill pipe line and on its other side providinga valve seat and with an enlarged valve guide receiving portion, a valveguide mounted within the enlarged portion and provided withscrew-threads, and a spring controlled valve interposed between thevalve seat and guide, said enlarged portion having similar interiorscrew-threads over an extended surface for engagement by those of theguide to accommodate'the mounting and adjustment of the guide andattachment of the body to drill pipe.

3. A drill pipe float joint comprising a box member and a pin member,said box member having a portion integral therewith and on the interiorthereof having a reduced bore therethrough and a valve seat on one sideand an abutment 0n the other side engaged by the pin member, an enlargedvalve guide receiving portion, a valve guide adj ustably mounted withinthe enlarged portion, and a spring controlled valve interposed betweenthe valve seat and guide.

In testimony whereof I aflix my signature.

JOHN D. LEMEX.

